services on ircd's can be some of the following
well starting from the beginning
NICKSERV, nickserv is where you can register you nick name useualyy with a /msg nickserv regsiter <e-mail address> <password> it is very good and use full to stop people from robbing ur nick name. also if you are logged ina dn for some strange reason then cut of the net and you come back in and u r logged in all ready you can use a ghost command to kill them of the server using /msg nickserv ghost <nick> <password>
CHANSERV, chanserv looks after your channel, also if you don't have botserv it wil atomaticaly op you when you join it will unban you if you use the /msg chanserv unban #<room> and you can add people to your channels access list through chanserv as well with a very easy command /msg chanserv access #<room> list but with all these services you can msg them with help and they will reply with a msg that you can seed to see what that service offers
BOTSERV, well this is just to make things easyer and faster through botserv you can use commands !op !Deop !voice !devoice !halfop !kick !ban !unaban and also a few more channel commands. this bot will also keep a channel topic lock on and will ato op you when you join even if you have chanserv it looks better for the bot to op you not the chanserv
HOSTSERV, this is very good and can make you look smarted all it realy dose is sets vhosts easyer so as ur ip address you could have instead of sox!sox-irc@25475.dialup.pol.co.uk you could have it set to sox!sox-irc@soxide.co.uk which looks better.
OPERSERV, This unless you are a ircop or a server admin is no use to you, but if you are this service speeds things up like adding msg's wallops and klineing and killing people of ur server but if you have this power and don't know how to use it I advice you to not use it untill some one who knows what they are doing can come and help you through it because you can seriusly mess up you server playing with operserv when you don't know how